The present invention relates to an apparatus for forming a carton for use as a container for liquids such as cow's milk, fruit juice or the like, filling the carton with the liquid, forming of the carton top and sealing of the same. More particularly, the present invention makes proposals concerning the device for shifting carton blanks with bottoms sealed in the above-mentioned apparatus to a bucket conveyor, construction of the bucket conveyor, construction of a folding device for shaping the top of the carton filled with the liquid and the construction of a device for treating the triangular projection (lug) formed when the carton top is formed into flat shape.
The apparatus for forming the carton, filling the carton, forming the carton top and sealing the same will be generally referred to as "automatic carton packing machine", hereinafter. The automatic carton packing machine is required to fulfill various requirements such as high treating capacity (yield), compactness, and so forth. In addition, the automatic packing machine is required to treat cartons irrespective of the shape of the latter.
In the conventional automatic carton packing machine, carton blanks with sealed bottom are placed in the frame of a chain conveyor one by one, and a series of operation such as filling of cartons with the liquid, formation of the carton top and sealing of the same is performed while the carton blanks are conveyed by the chain conveyor. Therefore, there is a practical limit in the speed of operation. Particularly, the step of shifting of the carton blanks with sealed bottom to the frame of the chain conveyor, after withdrawal of the same from the mandrel, is made at an extremely low efficiency to inconveniently limit the efficiency of the work.
There are two types of folding of the carton top after filling with the liquid: namely a flat top as shown in FIG. 1 and gable top as shown in FIG. 2. Hitherto, these shapes of the carton top are formed by different folding devices. In other words, for obtaining both of these two types of the carton top, it has been necessary to employ two different devices. In the case of the flat carton top as shown in FIG. 1, triangular projections or lugs are formed at each side of the carton top. It is necessary to fold these lugs down onto both side surfaces of the carton, because such lugs will hinder the transportation, storage and display of the cartons. To this end, it has been necessary to employ a suitable measure or arrangement such as provision of an elongated guide in the direction of running of the chain conveyor, to fold down the lugs toward the side surfaces of the carton. This requires, however, an impractically large length of the machine as a whole.